environment

$18m to save farmed wetland

Shovel-ready money made available due to Covid-19 could help fund a project environmentalists believe will have a negative effects

Environment advocates say there’s a difference between using Covid-19 economic stimulus cash to get ‘shovel-ready’ projects under way and using it to exhume bad ideas.

A project aiming to improve drainage on 1100 hectares of the Hauraki Plains is asking for government money and fast-tracked approval.

The estimated cost of the work has increased over the many years the project has lingered on council books from $3.5 million to $6m. The latest figure is $11m with a further $7 million included in overall works in the area for fish-friendly pumps.

Muggeridge’s pump station project is seeking $3 million from the Provincial Growth Fund. A further $6m is sought from the Government for fish-friendly pumps.

It has been put forward by the Waikato Regional Council as a project ready to go within the next six months but “dependent only on securing a shortfall in funding, due predominantly to construction sector increases. The impacts of Covid-19 include potential contractor shortages and further increases in cost as a result.”

The information submitted in the form explains the need for the drainage: 

“Without action, the area is estimated to be totally submersed within the next 50 years and uneconomic for some time prior to this due to ongoing peat settlement. Deterioration in profitability is estimated at 75 percent over a 30-year period.”

Around 20 properties are directly affected.

A landowner's submission to the project in 2018 when the cost increased from $3.5 million to $6 million.

Borrowed land on borrowed time

Removing water from the wetlands to enable farming has meant the peat has shrunk over time as it has dried. Some of the land is below sea level and it's estimated the shrinkage caused by the draining lowers the land two centimetres a year.

As a result, current pumps can’t keep up and the land borrowed from a wetland for farming is reverting to swamp.

Forest & Bird’s central North Island regional manager Rebecca Stirnemann points out sea level rise could render the $18 million investment obsolete in a couple of decades.

“We’re putting off the inevitable to try and engineer our way out of this.”

She worries the continued attempts to farm the wetland will allow the already poor water quality in the area to continue and sediment and excess nutrients to keep on polluting the Hauraki Gulf.

“The water systems there are some of the most polluted in New Zealand. We’ve also got the Hauraki Gulf, it’s not doing very well with the amount of sediment coming into it.”

A report released in February paints a grim picture of the state of the Hauraki Gulf. Nutrients from agriculture feature as one of the issues, with streams from the central Hauraki Plains getting special mention. 

The report notes: “Waikato Regional Council still hasn’t established a regular long-term monitoring programme for coastal water quality.”

In her mind, a better option would be for the council to purchase the land from the property owners and restore it to wetlands so it could provide ecosystem services and be used as a carbon sink. 

“The economics of this are ridiculous. The cost of drainage and the cost of pollution from the farms just won’t add up.”

Last week, Newsroom requested any previous cost benefit analyses of the project from the Waikato Regional Council. At the time of writing, this has not been supplied.*

Water quality issues in the area

The information shared by Waikato Regional Council to the Crown Infrastructure Partners regarding the process mentions diversification and sustainable land use as an outcome of the project. 

Two hectares of blueberry planting is mentioned. This equates to 0.18 percent of the 1100 hectares. A honey farm of 120 hives is also included as diversification. They are both listed as pilot programmes, with plans for potential expansion beyond 0.18 percent of land not included in the document.

Victoria University of Wellington freshwater scientist Mike Joy questions whether 2 hectares of 1100 and 120 beehives can be classed as diversification.

He worries farming intensification will be the main outcome of the project and called it an “ecological shocker”. Currently the land can’t be grazed all year round due to flooding. The pumps could increase grazing time.

“Any intensification, any additional cows on ground time there is going to exacerbate the problem.”

The area already has water quality problems, which were highlighted during summer when horrific pictures of dead eels and ducks emerged. A drought, high temperatures, closed flood gates and water pollution combined to create a hellscape.

Eels trapped by silted up floodgates drowned due to the lack of oxygen in the nutrient-rich water. It’s likely their corpses sparked a botulism outbreak. Carcasses of ducks joined the eels. 

To cap things off, a toxic algal bloom then occurred, thought to have killed vulnerable shore birds. These blooms happen when there are too many nutrients in the water.

Sick red knots were found in the Firth of Thames coinciding with two king tides, where sea water washes further inshore than usual. Of the 50 sick birds collected, around three-quarters were revived, but many perished. The suspected cause of their illness was either a toxic algal bloom or possibly botulism. 

The exact number of birds that died is unknown. In January, 1500 birds were seen roosting at high tide. By March, the number had dropped to between 300 and 500. This reduction occurred prior to their annual migration. 

During lockdown there was another king tide. Department of Conservation workers were unable to check for sick birds after this tide as it was deemed a non-essential government department.

This sick red knot died shortly after the photograph was taken. Photo: Supplied.

Fish friendly fish pumps

There’s scepticism from both Joy and Stirnemann about how friendly the fish pumps are.

Stirnemann believes the pumps are only “relatively” fish-friendly. 

Joy points out that with three-quarters of native fish already on the threatened species list, “we don’t need any more pumps going in anywhere”. He said the friendliness of the pump is dependent on the size of the fish going through it. 

A report prepared on behalf of Bedford Pumps, the pump brand shown in photographs related to the project, show good survival rates for fish for one of their pump designs. 

European eels were included in the experiments and all survived, the largest of these was 67 centimetres. This is around the average length of New Zealand’s male longfin eels.

Female longfin eels average 115cm, they make one lifetime migration to the sea when they are fully grown to breed before dying.

The projects put forward as possible shovel-ready candidates are currently being assessed by the Infrastructure Reference Group, which will prepare a list for potential funding. 

*Since publication the Waikato Regional Council has supplied the following information:

"The Muggeridge’s project has been on hold since the latter half of 2019 due to an increase in cost relating predominantly to the construction sector. The cost of the total Muggeridge’s programme is now around $9m, up from $6m. This increased cost is largely based on a sole market tender the council received for the construction of the pump station. As part of the shovel-ready bid, an extra $2 million has been sought for restoration work."

A final recent cost benefit analysis has not been completed but an economic re-evaluation in late 2019 supports a capital expenditure of up to nearly $8m to be economically viable.

*This story has been updated to clarify the cost split between the Muggeridge Pump Station project and the fish friendly pumps.

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